3,592 research outputs found
Anomalous Dimensions from a Spinning D5-Brane
We consider the anomalous dimension of a certain twist two operator in N=4
super Yang-Mills theory. At strong coupling and large-N it is captured by the
classical dynamics of a spinning D5-brane. The present calculation generalizes
the result of Gubser, Klebanov and Polyakov (hep-th/0204051): in order to
calculate the anomalous dimension of a bound state of k coincident strings, the
spinning closed string is replaced by a spinning D5 brane that wraps an S4
inside the S5 part of the AdS5 times S5 metric.Comment: 8 pages, LaTex. v2: figure added. minor changes. To appear in JHE
't Hooft Expansion of 1/2 BPS Wilson Loop
We revisit the 't Hooft expansion of 1/2 BPS circular Wilson loop in N=4 SYM
studied by Drukker and Gross in hep-th/0010274. We find an interesting
recursion relation which relates different number of holes on the worldsheet.
We also argue that we can turn on the string coupling by applying a certain
integral transformation to the planar result.Comment: 21 pages; v2: minor correction
Open String Star as a Continuous Moyal Product
We establish that the open string star product in the zero momentum sector
can be described as a continuous tensor product of mutually commuting two
dimensional Moyal star products. Let the continuous variable parametrize the eigenvalues of the Neumann matrices; then the
noncommutativity parameter is given by .
For each , the Moyal coordinates are a linear combination of even
position modes, and the Fourier transform of a linear combination of odd
position modes. The commuting coordinate at is identified as the
momentum carried by half the string. We discuss the relation to Bars' work, and
attempt to write the string field action as a noncommutative field theory.Comment: 30 pages, LaTeX. One reference adde
Linear Sigma Models of H and KK Monopoles
We propose a gauged linear sigma model of k H-monopoles. We also consider the
T-dual of this model describing KK-monopoles and clarify the meaning of
"winding coordinate" studied recently in hep-th/0507204.Comment: 13 pages, lanlmac; V3:added argument on the nature of disk instanto
Ratio of Tensions from Vacuum String Field Theory
We show analytically that the ratio of the norm of sliver states agrees with
the ratio of D-brane tensions. We find that the correct ratio appears as a
twist anomaly.Comment: 13 pages, lanlmac; version to appear in JHE
BPS Wilson Loops on S^2 at Higher Loops
We consider supersymmetric Wilson loops of the variety constructed by
Drukker, Giombi, Ricci, and Trancanelli, whose spatial contours lie on a
two-sphere. Working to second order in the 't Hooft coupling in planar N=4
Supersymmetric Yang-Mills Theory (SYM), we compute the vacuum expectation value
of a wavy-latitude and of a loop composed of two longitudes. We evaluate the
resulting integrals numerically and find that the results are consistent with
the zero-instanton sector calculation of Wilson loops in 2-d Yang-Mills on S^2
performed by Bassetto and Griguolo. We also consider the connected correlator
of two distinct latitudes to third order in the 't Hooft coupling in planar N=4
SYM. We compare the result in the limit where the latitudes become coincident
to a perturbative calculation in 2-d Yang-Mills on S^2 using a light-cone
Wu-Mandelstam-Leibbrandt prescription. We are not able to calculate the SYM
result at the required order in the separation between the latitudes necessary
for a match with 2-d Yang-Mills; the result, however, does not preclude such a
match.Comment: 39 pages, 15 figures. v2 references added, minor cosmetic changes. v3
minor error in eq. (40) corrected. v4 error in coincident limit of correlator
corrected; claims of disagreement with 2-d Yang-Mills retracte
<Session 5: Wildlife Tracking I>Simultaneous measurements of breaths and energy expenditure reveal the dive tactics of sea turtles
19â22 May 2022 Kyoto, JapanAir-breathing divers are assumed to have evolved to apportion their time between surface and underwater periods to maximize the benefit gained from diving activities. However, whether they change their time allocation depending on the aim of the dive is still unknown. This may be particularly crucial for 'surfacers' because they dive for various purposes in addition to foraging. In this study, we counted breath events at the surface and estimated oxygen consumption during resting, foraging, and other dives in 11 green turtles (Chelonia mydas) in the wild. Breath events were counted by a head-mounted acceleration logger or direct observation based on an animal-borne video logger, and oxygen consumption was estimated by measuring overall dynamic body acceleration. Our results indicate that green turtles maximized their submerged time, following this with 5-7 breaths to replenish oxygen for resting dives. However, they changed their dive tactic during foraging and other dives; they surfaced without depleting their oxygen content, followed by only a few breaths for effective foraging and locomotion. These dichotomous surfacing tactics would be the result of behavioral modifications by turtles depending on the aim of each dive
Semi-classical open string corrections and symmetric Wilson loops
In the AdS/CFT correspondence, an AdS_2 x S^2 D3-brane with electric flux in
AdS_5 x S^5 spacetime corresponds to a circular Wilson loop in the symmetric
representation or a multiply wound one in N=4 super Yang-Mills theory. In order
to distinguish the symmetric loop and the multiply wound loop, one should see
an exponentially small correction in large 't Hooft coupling. We study
semi-classically the disk open string attached to the D3-brane. We obtain the
exponent of the term and it agrees with the result of the matrix model
calculation of the symmetric Wilson loop.Comment: 14 pages, 4 figures. v2: explanation improved. v3: argument in
section 2 is improved, result not change
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